The domain of this invention is remote services offered by telecommunications operators to their customers subscribing to their network.
More precisely, the invention relates to a method and a system enabling a telecommunications operator to quickly identify subscribers to a telephone network, and to reliably debit their accounts.
The problem that arises is to prevent a dishonest user from accessing the telecommunications network without being authorized to do so, without paying the corresponding costs, or from claiming that he did not request the services that were debited to him by the telecommunications operator.
To solve this problem it has been proposed to use access keys generated by memory cards and to modify telephone handsets so that they can read the memory cards. Apart from their costs, these solutions are not very practical and take a long time to set up. The problem that arises can only really be solved if a solution is known to another problemxe2x80x94how to design a method and system that is convenient to use and that can be quickly and economically installed. Ease of use and time savings are major problems for any product aimed at the general public, and cannot be ignored.
A proposal has been made (document WO 96 04741 in the name of Andrew MARK) to use a card emitting encrypted DTMF type acoustic signals. Thus, the holder of this card can couple it to the microphone in a telephone handset, to automatically transfer his identifiers to computer services. Since these identifiers are encrypted, a third party should not be in a position to understand the contents.
However, there is nothing to stop the signals emitted by the card from being recorded, and a defrauder in possession of this type of recording could substitute himself for the card holder.
Therefore, if A. MARK""s solution were transposed to the case of telecommunications operators wishing to quickly and reliably identify subscribers to their networks, would not prevent a dishonest user from accessing the services offered by telecommunications operators, without authorization.
The objectives of this invention are achieved, and the problems that arise with techniques according to prior art are solved according to the invention by means of a method comprising the following steps:
the telecommunications operator provides each of its subscribers with a subscriber card, the same size as a credit card, customized by identifiers specific to each subscriber and to each subscriber card,
the said card, the same size as a credit card, emits short acoustic DTMF type identification signals, at least partly encrypted and varying for each operation, when the subscriber uses it,
acoustic identification signals are received by the microphone in the telephone handset and are converted into electrical signals before being transmitted through the communications network to the telecommunications operator""s computer service,
the transmitted signals and the customer and card identification data stored by the computer service are methoded and electronically compared by the telecommunications operator""s computer service.
Thus with this method, the telecommunications operator can verify that the caller actually has an authentic card and not a computer artifice. He can also identify the card holder as being a person authorized to use the offered services. Consequently if the results are conform, the customer is immediately connected the voice server or the telecommunications operator""s receptionist. Furthermore, defrauders cannot determine identification data since they were automatically transmitted in encrypted form. Furthermore, with the recorded acoustic signals in any form whatsoever, a defrauder will be unable to identify himself to the telecommunications operator and benefit from its services. The acoustic identification signals are different for each operation, in other words every time that the card is used.
Preferably the said card:
also counts the number of times C(p,n) that it is used,
emits acoustic signals representing the number of times C(p,n) that it has been used,
encrypts acoustic signals as a function of the number of times C(p,n) that it has been used.
Also preferably, the said computer means for methoding and electronically comparing the transmitted signals and the customer and card identification data held by the telecommunications operator""s computer service,
store the number of times C(p,m) that the card has been used at the time of the last validated operation,
compare the number of times C(p,n) that the card has been used at the time of the current operation, with the memorized number of times N1,
refuse the current operation if C(p,n) is less than or equal to C(p,m) and continue verifying the current operation if C(p,n) is greater than C(p,m),
recalculate electronic signals S"" (p,n) as a function of identification data and the number of times C(p,n) that the card was used, during the current operation, and then compare them with the transmitted electronic signals S (p,n). If the values agree, the subscriber may then immediately be connected to the telecommunications operator""s services.
In order to increase security, in one variant embodiment, the method also comprises a step in which the subscriber uses a keypad associated with the telephone handset and/or the card to send a pin code. After transmission to the telecommunications operator""s computer service through the communications network, this pin code is methoded and compared with the subscriber""s pin code held by the telecommunications operator""s computer service.
Thus the telecommunications operator can check that the caller is actually the person authorized to be connected to its services. A stolen card cannot be used by the thief, since he does not know the pin code.
In another variant embodiment also designed to increase security of the method and to make it impossible for the customer to dispute the order that he made to the telecommunications operator, the method also includes the following steps:
orders given by the subscriber to the telecommunications operator are validated by the subscriber by using the subscriber card so that it sends an encrypted acoustic validation signal,
the telecommunications operator""s computer service records the said validation signal.
Advantageously, the method according to the invention may include the following additional step:
an acknowledgment of the validation signal is sent to the customer.
With this method, the subscriber used an electronic signature to validate the order that he gave to the telecommunications operator.
The invention also relates to a system enabling subscribers to a telecommunications network to quickly and reliably access services offered by the telecommunications operator to his customers. This system is capable of understanding the means of implementing the method described above and its variant embodiments.
More particularly:
The system according to the invention comprises a subscriber card, the same size as a credit card, customized by specific identifiers for each subscriber card and for each subscriber, provided by the telecommunications operator. The said card comprises means of emitting short acoustic identification signals of the DTMF type. The subscriber controls the emission means using an element accessible from the outside of the subscriber card. The card also comprises encryption means in order to encrypt at least part of the acoustic signals, and to vary them whenever the card is used.
The system according to the invention comprises a telephone handset comprising a microphone used to receive acoustic signals, and to transform them into electrical signals that can be transmitted through the communications network.
The system according to the invention also comprises computer means dependent on the telecommunications operator""s computer services connected to the telecommunications network. The said computer means comprise:
* a database containing the references of the subscriber cards and subscribers and their identification data,
* methoding means and means of comparing the transmitted electronic signals and identification data contained in the database. Thus with this system, the telecommunications operator can verify that the caller has actually an authentic card and not a computer artifice. He can also identify the card holder as a person authorized to use the services that he offers. Consequently if the card is conform, the customer will immediately be connected to the voice server or the telecommunications operator""s receptionist. Furthermore, defrauders can no longer determine identification data since they were automatically transmitted in encrypted form. Furthermore, a defrauder will not be able to identify himself to the telecommunications operator""s computer services using a recording of the acoustic signals in any form whatsoever, since the acoustic identification signals vary during each operation, in other words every time that the card is used.
Preferably, the card also includes:
an incremental counter interconnected to emission means and encryption means that is incremented by at least one unit every time that the card is used.
Consequently, the state of the incremental counter is sent to the computer means and acoustic signals are encrypted as a function of the state of the incremental counter. Preferably, the said computer means also comprise:
means of memorizing the state C(p,m) of the incremental counter at the time of the last validated operation.
means for comparing the state C(p,n) of the incremental counter emitted during the current operation with the state C(p,m) of the memorized incremental counter.
Consequently, the check on the current operation is refused if C(p,n) is less than or equal to C(p,m) and is accepted if C(p,n) is greater than C(p,m).
Also preferably, the said methoding means and the said means of comparison of the electronic signals and identification data contained in the database include means of recalculating the electronic signals as a function of the state C(p,n) of the incremental counter and the identification data, and then comparing them with the transmitted electronic signals. Consequently if agreement is found, the subscriber can immediately start communications with his correspondent or with the telecommunications operator""s services.
In one variant embodiment designed to increase the security of the system, the system also comprises second means of comparing a subscriber""s pin code stored in the database, with a pin code input by the subscriber. This code is emitted by means of a keypad associated with the telephone handset and/or the card, and is transmitted to the telecommunications operator""s computer means, through the communications network.
Thus, the telecommunications operator can verify that the caller is actually the person authorized to access the services. A thief cannot use a stolen card because he does not known the pin code.
In another variant embodiment, also designed to increase the security of the system and to make it impossible for the customer to dispute an order that he gave to the telecommunications operator, the system according to the invention is such that:
when the subscriber activates the said card, it emits an encrypted acoustic signal to validate orders given by the subscriber,
the said computer means include means of detecting and recording the validation signal.
With this system, the customer validated the order that he made to the telecommunications operator with an electronic signature.
Advantageously, in this case the computer means also include means of printing an acknowledgment of orders made. This acknowledgment is addressed to the subscriber.